Answer:
Ammonia is the richest source of nitrogen on a mass percentage basis because it has 82.35% of nitrogen by mass.
Explanation:
Percentage of element in compound :

(a) Urea, 
Molar mass of urea = 60 g/mol
Atomic mass of nitrogen = 14 g/mol
Number of nitrogen atoms = 2

(b) Ammonium nitrate, 
Molar mass of ammonium nitrate = 80 g/mol
Atomic mass of nitrogen = 14 g/mol
Number of nitrogen atoms = 2

(c) Nitric oxide, NO
Molar mass of nitric oxide = 30 g/mol
Atomic mass of nitrogen = 14 g/mol
Number of nitrogen atoms = 1

(d) Ammonia, 
Molar mass of ammona = 17 g/mol
Atomic mass of nitrogen = 14 g/mol
Number of nitrogen atoms = 1
Ammonia is the richest source of nitrogen on a mass percentage basis because it has 82.35% of nitrogen by mass.
Answer:
I dont know if this is correct.. but maybe in the tool row, put graduated cylinder because you use graduated cylinders to measure water and for units put milliliters or liters?? Sorry if this isnt correct i wouldnt know what else to put !
Explanation:
Answer is: <span>the molarity of the diluted solution 0,454 M.
</span>V₁(NaOH) = 100 mL ÷ 1000 mL/L = 0,1 L.
c₁(NaOH) = 0,75 M = 0,75 mol/L.
n₁(NaOH) = c₁(NaOH) · V₁(NaOH).
n₁(NaOH) = 0,75 mol/L · 0,1 L.
n₁(NaOH) = 0,075 mol
n₂(NaOH) = n₁(NaOH) = 0,075 mol.
V₂(NaOH) = 165 mL ÷ 1000 mL/L = 0,165 L.
c₂(NaOH) = n₂(NaOH) ÷ V₂(NaOH).
c₂(NaOH) = 0,075 mol ÷ 0,165 L.
c₂(NaOH) = 0,454 mol/L.
Every isotope of an element has a different number of neutrons, which means that the atomic property which is different in each isotope of an element is mass number.
Mass number depends on the number of neutrons in an element.